Alpine CDA-7878R owner manual Crossover/Time Correction

Adjusting the Sound Operation

The Crossover/Time Correction

Crossover:

This unit is equipped with an Active Crossover. The crossover limits the frequencies delivered to the outputs. Each channel is controlled independently. Thus, each speaker pair can be driven by the frequencies for which they have been optimally designed.

The divider adjusts the HPF (high pass filter) or LPF (low pass filter) of each band, and also the slope (how fast the filter rolls off the highs or lows).

Adjustments should be made according to the reproduction characteristics of the speakers. Depending on the speakers, a passive network may not be necessary. If you are unsure about this point, please consult your authorized Alpine dealer.

2 way mode

	Cut-off frequency		Slope
	(1/3 octave steps)				Level
	HPF	LPF	HPF	LPF
Low range				FLAT, 6,
	----	20 Hz -	----	12, 18,	0 to
speaker		200 Hz		24 dB/	−12 dB
				oct
Front high			FLAT, 6,
	20 Hz -	----	12, 18,	----	0 to
range	200 Hz		24 dB/		−12 dB
speaker
			oct
Rear high			FLAT, 6,
	20 Hz -		12, 18,		0 to
range		----		----
	200 Hz		24 dB/		−12 dB
speaker
			oct

3 way mode

	Cut-off frequency		Slope
	(1/3 octave steps)				Level
	HPF	LPF	HPF	LPF
Low range				FLAT, 6,
	----	20 Hz -	----	12, 18,	0 to
speaker		200 Hz		24 dB/	− 12 dB
				oct
Mid range			FLAT, 6,	FLAT, 6,
	20 Hz -	20 Hz -	12, 18,	12, 18,	0 to
speaker	200 Hz	20 kHz	24 dB/	24 dB/	−12 dB
			oct	oct
High			FLAT, 6,
	20 Hz -		12, 18,		0 to
range		----		----
	20 kHz		24 dB/		−12 dB
speaker*
			oct

∗When setting the high range HPF filter to FLAT, do not turn up the volume too much. This may damage the speaker.

Low range High range

(Different from actual display)

Output frequency range

Low range Mid range High range

(Different from actual display)

			Slope FLAT
Level adjusting		Slope adjusting
(0 to - 12 dB)
20 Hz		(Different from actual display)
	LPF cut-off	HPF cut-off
	frequency	frequency

NOTES

•HPF (high pass filter): Cuts the lower frequencies and allows the higher frequencies to pass.

•LPF (low pass filter): Cuts the higher frequencies and allows the lower frequencies to pass.

•Slope: The level change (in dB) for a frequency change of one octave.

•The higher the slope value, the steeper the slope becomes.

•Adjust the slope to FLAT to bypass the HP or LP filters.

•Do not use a tweeter without the HPF on or set to a low frequency, as it may cause damage to the speaker due to the low frequency content.

•You cannot adjust the crossover frequency higher than the HPF or lower than the LPF.

30-EN